The present invention relates to a method of and an apparatus for specifying an observing or working position which specify, as to a position indicated by an electronic or digitized data of a sample a corresponding position by an observation image of the sample, and to a method and an apparatus for working a sample.
As a method of performing an observation or working of the sample by a scanning charge particle microscope, an optical microscope and the like, there is the fact that the observation or working is performed by the scanning charged particle microscope, the optical microscope and the like by indicating a desired observing or working position by using the observation image obtained by other observation apparatus and a layout drawing of the sample or, in the sample such as semiconductor device, a CAD data of the sample.
For example, in a case where the observation of the sample is performed by a charged particle beam apparatus, a secondary electron image obtained by scan-irradiating a charged particle beam to the sample is an image mainly resulting from a step of a sample surface. Accordingly, the observation of the sample whose surface is flat or a portion existing in a lower layer of the sample comprising a multi-layer structure cannot be displayed to the secondary electron image. Whereupon, as a method of observing the semiconductor device having a layer structure, there is disclosed a method of determining the observing position by a synthesized image by image-synthesizing the secondary electron image of a surface of the semiconductor device and an image of a design data by using the design data of the semiconductor device (for example, refer to Patent Document 1).
Further, as a method of working the semiconductor device having the layer structure, there is disclosed a method of working by a focused ion beam by forming a mark in the vicinity of the working position, measuring a relative distance between the mark and the working position by the optical microscope, and indicating the working position by referring to a measurement result and a position of the mark (for example, refer to Patent Document 2).
[Patent Document 1] JP-A-9-147780 Gazette
[Patent Document 2] JP-A-10-303199 Gazette
However, in the method of determining the observing position by image-synthesizing the secondary electron image of the surface of the semiconductor device and the image of the design data, in order to image-synthesize, it has been necessary to coincide a magnification of the secondary electron image with that of the design data. On that occasion, a magnification accuracy of the charged particle beam apparatus influences a position specifying accuracy, so that it has been difficult to accurately specify the observing position. Further, since image-synthesized, a time has been required.
Further, in the method of specifying the worked position from the measurement result by forming the mark in the vicinity of the worked position, and measuring the relative distance between the mark and the worked position by the optical microscope, since the worked position is determined on the basis of the relative distance measured by the optical microscope, a measurement accuracy of the optical microscope influences a working position specifying accuracy, so that it has been difficult to accurately specify the working position.
The present invention attempts to solve the foregoing problems with the conventional method and apparatus, and an object is to accurately and simply specify the observing or working position.